1. Field of the Invention
The present invention relates to a hole-burning material and a method for producing the same. More particularly, the present invention relates to a hole-burning material which utilizes the hole-burning phenomenon of color centers in diamond and a method for producing such diamond hole-burning material.
2. Description of the Related Art
Hitherto, organic dyes such as porphyrins and quinizarin (1,4-dihydroxyanthraquinone) contained in a matrix such as n-hexane are used as hole-burning materials (cf. "KAGAKU TO KOGYO" (Chemistry and Industry), Vol. 35, No. 9 (1982) 633-635). In use, such the organic dye base hole-burning materials should be cooled to the liquid helium temperature, and most of them have such defect that the once-formed holes have short life. If the hole-burning materials have holes with a semipermanently long life, the holes cannot be erased at low temperature. To erase such long-life holes, the hole-burning material should be heated up to around room temperature. However, all the holes are erased by heating the hole-burning material.
In addition to the organic dyes, alkali halide compounds are irradiated with electron beam to create the color center and used as hole-burning materials. Again, such the alkali halide base hole-burning materials have the same defects as the organic dye base hole-burning material.
Alternatively, R. T. Horley et al reported the hole-burning phenomenon observed in diamond having various color centers such as GRI, N-V, H3 or N3 color center (cf. J. Phys., C: Solid State Phys., 17 (1984) 233-235. The conventional diamond hole-burning material has the below described drawbacks.
(1) At a temperature higher than 20 K., the holes disappear.
(2) The holes disappear within about 15 minutes even at a temperature of 20 K. or lower.
(3) At the temperature at which the holes can exist, the holes formed in a single spot cannot be erased without erasing the holes formed in other spots.
(4) The holes should be detected with microwave.
(5) A hole with a large depth cannot be formed.
(6) At a temperature higher than 77 K., plural holes cannot be burnt simultaneously.